Governor utilizing leaf spring responsive to throw of governor weights



y' 1954 R. J. REEK 2,683,597

GOVERNOR UTILIZING LEAF SPRING RESPONSIVE T0 THROW OF GOVERNOR WEIGHTSOriginal Filed Aug. 1, 1946 //V|/ENTOR. R074! (A Eff/a jrraR/vsy.

Patented July 13, 1954 UNITED STATES PATENT OFFICE GOVERNOR UTILIZINGLEAF SPRING RE- SPONSIVE TO THROW OF GOVERNOR WEIGHTS corporation ofDelaware Continuation of application Serial No. 687,780,

August 1, 1946. This a Serial No. 230,215

4 Claims.

This invention relates to speed sensing devices or governors responsiveto the speed of its driving apparatus for controlling a mechanism.

This application is a continuation of my application Serial No. 687,780,filed August 1, 1946, now abandoned.

It is an important object of the invention to provide a governorresponsive to its driving apparatus for controlling a switch which formsa part of an electrical system.

Another important object of the invention resides in the provision ofcentrifugally controlled switch.

A further important object of the invention resides in the provision ofa centrifugally controlled switch which may be adjusted to vary itsopening and closing cycle.

Another object of the invention is to provide a device having theseadvantages and capacities, and which is, compact, and closely organizedin construction, reliable and effective in operation, convenientlyadjustable and adapted to be economically manufactured.

Other objects and advantages reside in certain novel features of theconstruction, arrangement and combination of parts which will behereinafter more fully described and particularly pointed out in theappended claims, reference beinghad to the accompanying drawing forminga part of this specification, and in which;

Figure 1 is a view in section of the device of the invention, with partsshown in elevation;

Figure 2 is a view in perspective of the rotating member of the device;

Figure 3 is an elevational view of the rotating member; and

Figure 4 is a modified form of the centrifugally operated mechanism.

Referring to the drawing, reference numeral I designates a housinghaving a cover [2, secured thereto by screws l4. The housing is formedto provide a boss 16 which is bored at l8 to receive a sleeve 28,recessed at 22 to serve as a bearing for a rotatable shaft 24. The bossis threaded at 25 to enable mounting the housing securely in place. Theshaft 24 may be connected, in any suitable manner, to a mechanism, notshown, the speed of which is to be sensed.

The cover I2 carries a single pole double throw switch 28 locatedinteriorly thereof. The switch pplication June 6, 1951,

comprises a blade 30 normally biased downwardly, as viewed in thedrawing, toward terminal 32, but urged into contact with terminal 34 bycentrifugally operated mechanism 36. The blade 30 is securely held tothe cover i2, in any suitable manner, such as by a rivet 38 which alsoforms a conductor for passing current to the blade 30. A lug 40, intowhich electrical conductors may be inserted, is held in place to theexterior of the cover by the rivet 38. The terminals 32 and 34 areelectrically connected to the exterior of the cover by rivets 42 and 44respectively. The rivets 42 and 44 engage lugs 45 and 48 respectively atone end and the terminals 32 and 34 at the other end. It should bepointed out that instead of operating the switch 28 the centrifugallyoperated mechanism could be made to move a lever to operate a valve, notshown, or to move a member, not shown, to start a chain of events whicheiTects control of the driving mechanism, not shown.

The centrifugally operated mechanism 36 is suitably fastened to theshaft 24 in any manner, as shown. The mechanism comprises an over centerspring or toggle arrangement 50 formed from a U-shaped element havingits parallel sides 52 and 54 secured to a base plate 56 mounted on theshaft 24. The U-shaped element is slotted at 58 and 69 to provide amember 62 fixed at both ends to the element and formed to be longer thanthe length of the slots 58 and 60 to thereby cause the member to bulgeor seek an arcuate form. Member 62 is formed in a manner to provide aspring having a negative rate or characteristic. That is, as the sprinis bent downwardly to ward an over center position its resistance tobending decreases. The switch blade 30 carries a button 6!, made ofinsulating material, and normally is in contact with the member 62,whereby the blade is held out of contact with the terminal 32 and incontact with the terminal 34. In the present invention the member 62 isdeflected downwardly at its center under the centrifugal action ofweights 64 and 68 which are clamped or otherwise fixed to the member 62.These weights are suspended from the member 62 with their pivot pointsoffset radially from the axis of rotation of the shaft. The bias of thespring-like member 62 is such that the bulge is normally in thedirection shown in the drawing,

Figures 1 and 2. The base plate 55 is cut out at 38 and is toaccommodate the ends of the suspended weights B4, and 66 which aredrilled and tapped at 1'2 and M to receive adjusting screws 16 and '58to vary the center of gravity of the Weights and consequently the lengthof their moment arms. This adjustment varies the centrifugal forceapplied by the weights for moving the member 62 from the position shownin Figure 2 to that shown in Figure 3 and, therefore, controls the highspeed at which the governor responds. Adjusting screws 30 and 82 arediametrically disposed in the parallel sides of the U-shaped element ina mannerto limit the outward swing or throw of the weights to therebycontrol the speed range of the mechanism. That is, since the radius ofgyration of the weightsincreases as they move away from ,the'center ofrotation in response to a predetermined shaft speed it follows that theshaft speed must be rereduced below said predetermined speed to allowthe weights to return. The: amount of reduction in shaft speed belowsaid predetermined value will, of course, depend upon theincrease-inradius of gyration or the distance the Weights have moved outfrom their center of rotation and the characteristic of the spring-likemember, 62. To increase the speed range of the governor, screws and 82are turned outwardly with respect to the sides 52 and 3 and .vice Versato decrease the speed range. This adjustment controls the low speed atwhich the governorresponds. It will thus be noted that either adjustmentindependently controls the speed range, that is, the overall speed rangeof the governor. Stating it another way, either adjustment will vary thedifferential between high and low governor speeds.

The relationship between the blade. 38 and the member are is such thatwhen the member reaches a lrinematically unstable condition there willstill remain a substantial contact pressure between the blade 38 and thecontact'34.. This prevents fluttering of the blade 39 and henceeliminates premature making and breakingof the contacts.

Figure 4 illustrates a modified form of the centrirugally operatedmechanism compri g a supporting element 36 having abase 92 'Wlbl'l aboss Bil adapted to lit the shaftj2 l to. securely fasten themechanismthereto. The base 92 has sides 96 and 98 integral therewith andnotched at iilil and it? to receive the ends of a preformed spring-likemember as; having a negative rate. The weights E i and 66 are suspendedfrom the member 564 in any suitable manner, as shown. Due to the centriugal action of the weights when the shaft rotates at predeterminedspeeds, the spring 534 is flexed downwardly. A tension ing screw E66passes through side 95 andthreadedly engages side 98. to thereby holdthe-sides relatively rigid. The screw also provides .adjusting means forvarying the actuating force of spring we upon the blade 36. Thespringlii l has a diminishing rate characteristic, which can be variedby. adjusting means shown in the form of a threaded bolt or red ice,connecting the sides or side portions 96 and 93 of the U- haped member96. By adjusting the bolt or rod N36 to decrease the spacing of thesidestli and GS of U-shaped member, the spring rate of the leaf springits may be increased, the opposite effect resulting from an increase inthe spacing of said sides or side portions 96 andefi. .Changing the ratecharacteristic of the .spring .564 varies the speed range of thedevice.

Operation. and adjustment of. the. mechanism is as follows: With theparts in the position shown in Figures 1 and 2, screws it and it areadjusted, so that at a preselected speed of the driving shaft 2:3, theweights will cause the 5 member 62 to assume the position shown inFigure 3, at which time, an electrical connection is made between theblade 36 and contact This adjustment takes care of the up speed of thegovernor. After selecting the down speed or speed range desired thescrews as and 32 are adjusted. If for example, it is decided to increasethe speed range, that is, make the switch operate at a lower governorspeed from that shown in Figure 1, screws=3ii and 82 would be turnedoutwardly to thereby allow a greater radius of gyration of the weights.

Although this invention has been described in connection with certainspecific embodiments, principles are susceptible of numerous otherapplications that will readily occur to persons skilled in the art. Theinvention is, therefore, to be limited only as indicated by the scope ofthe appended claims.

-Having thus described the various features of the invention, what Iclaim as new and desire to secure by LettersPatent is:

1. A speed sensing device comprising a rotatable element,meanscontrolled by the speed of the element within apredetermined speedrange, centrifugally actuated means mounted for rotation by said elementand comprising a U shaped member having spaced side portions, a .leafspring suspended .by. its. ends on the side portionsof saidU-shapedmember in a manner such as to provide said spring with adiminishing rate characteristic, said spring being arin operativerelationship with said first named means, a pair of Weights, onecarried. on each end of said spring adjacent the points of r0.suspension,v and an. adjustable connection be tween the sides of theU-shaped member for changing the rate characteristic of the spring.

2. A speed sensing device. comprising a rotatable element, meanscontrolled by the rota- 5 tional speed of. the element within apredetermined speed range, centrifugally. actuated means carried by saidelementand respomive to the speed thereof comprising a U-shaped .memberhaving spaced side portions, aleaf spring supportedatits ends betweenthe side portions ofsaid member in a manner to provide said spring witha diminishing rate characteristic, said leaf spring being. arranged inoperative relationship with said first namedmeans, a pair of Weights,

one swingably suspended .oneach end of said leaf spring andpositionedinside the points of support and contiguous thereto,.. meanscarried at the free end of each weight forchanging the length of itsmoment arm, and means connecting so the, side portions of. said U-shapedmember for varying the rate characteristic of said leaf spring.

3.. A speed sensing device comprising. a rotatable element, meanscontrolled by the rotational speed of the element within a predeter- 5mined speed range, centrifugally actuated means to, said portions andlocated in operative. relationship with. said nrst-namedgmeans, sideportions being so spaced as to maintain the spring under compressionwith .a diminishingratecharacteristic asthe. spring flexes toward deadcenter,

.75. a..pair of elongated weights-secured to opposite ends of said leafspring adjacent the points of connection of the spring to said sideportions, said weights having radially-outwardly swingable portionsdepending between the side portions of the U-shaped member, meanscarried by the swingabie portions of each weight for varying its momentarm, and means supported by the side portions of the U-shaped member forlimiting the outward throw of said weights.

4. A speed sensing device as claimed in claim 3 wherein means areprovided for adjusting the spacing of the side portions of said U-shapedmember to thereby adjust the rate characteristics of said leaf spring.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date Crabb Mar. 2, 1920 Tomiinson May 9, 1922 Tomiinson May 9, 1922Tomlinson Oct. 24, 1922 Parsons Sept. 2, 1924 Sole June 27, 1933 WrightMar. 4, 1947 Vacha Oct. 28, 1952

